"""
parse commandline output, reconstruct a filesystem and determine the sum of all folders < 100kB
"""

TESTRUN = True

test_text = """$ cd /
$ ls
dir a
14848514 b.txt
8504156 c.dat
dir d
$ cd a
$ ls
dir e
29116 f
2557 g
62596 h.lst
$ cd e
$ ls
584 i
$ cd ..
$ cd ..
$ cd d
$ ls
4060174 j
8033020 d.log
5626152 d.ext
7214296 k
"""

with open('2022/7/stdout.txt') as filein:
    input_text = filein.read()

text = test_text if TESTRUN else input_text


def parse_stdin(stdin: str):
    outputs = stdin.split('$')
    outputs = [[line.strip() for line in output.splitlines()] for output in outputs if output]
    return recursive_parse(outputs)


def recursive_parse(outputs: list):
    structure = {}
    while True:
        try:
            current = outputs.pop(0)
        except IndexError:
            return structure
        command = current.pop(0)

        if command.startswith('ls'):
            content = [c.split() for c in current]
            for value, name in content:
                structure[name] = int(value) if value.isnumeric() else value

        elif command.startswith('cd'):
            destination = command.split()[1]
            if destination == '..':
                return structure
            else:
                structure[destination] = recursive_parse(outputs)


def recursive_sum(d: dict, folders: list = None, initial=True):
    s = 0
    folders = [] if folders is None else folders

    for name, value in d.items():
        if isinstance(value, dict):
            zs = recursive_sum(value, folders, False)
            folders.append((name, zs))
        else:
            zs = value
        s += zs

    if initial:
        return folders
    else:
        return s


def folders_up_to_size(folders: list, size: int):
    return [(k, v) for k, v in folders if v <= size]


def recursive_print(d: dict, indent=0, increment=2):
    for k, v in d.items():
        if isinstance(v, dict):
            print(' '*indent, 'dir', k)
            recursive_print(v, indent+increment)
        else:
            print(' '*indent, k, v)


system = parse_stdin(text)
# recursive_print(system)
sums = recursive_sum(system)
summed_folders = folders_up_to_size(sums, 100000)
print(summed_folders)
print(sum([v for _, v in summed_folders]))

"""
now find the smallest folder that can be deleted to free up the space needed to keep the total size under 40MB
"""


def folders_over_size(folders: list, size: int):
    return [(k, v) for k, v in folders if v > size]


total = sums[-1][1]
over = total-40000000
print('filesystem overfull by:', over)

summed_folders = folders_over_size(sums, over)
summed_folders.sort(key=lambda x: x[1])
print(summed_folders[0])